ABSTRACT
Polyvinyl chloride (PVC) is the most widely used of the thermoplastic polymers. There are two main types of homopolymer available: rigid or unplasticized; and flexible which contains plasticizer. PVC’s stereo-isomerie form are mainly atactic with a small amount of chain branching. Polymerization processes used for the production of PVC are: suspension, emulsion, mass or bulk, and solution. Because of PVC’s rigidity and limited heat stability, additives are incorporated into the resin prior to processing. The polymer migrates to form PVC particles in water stabilized by the emulsifiers present. Items made from rigid PVC include pipe and conduit fittings, automobiles, blow moulding and roofing tiles. Two types of the homopolymer are produced: flexible which accounts for around 60% of PVC demand, and rigid. Flexible PVC finds outlets in calendered sheet, wire and cable coating, flooring, coated fabrics, shower curtains, automobile upholstery and furniture. Inhalation of PVC causes damage to lungs and liver.
